In cellular networks, a cell may suffer co-channel interference from one or more neighboring cells. In some cases, the co-channel interference may be a dominant limiting factor for achieving higher network efficiency, for example, for cell edge users.
Downlink (DL) Coordinated Multi-Point (CoMP) schemes attempt to address the inter-cell interference, by using coordination schemes on a network side to coordinate between transmitting nodes. The DL CoMP schemes assume an Evolved Node B (eNB) architecture with multiple remote radio heads (RRH), a central processing unit, which is responsible for signal processing and coordination of RRHs, and ideal, e.g., high capacity and low latency, backhaul links to connect between the RRHs and the central processing unit. However, usage of the DL CoMP schemes may be limited to very specific deployments, since ideal or close-to-ideal backhaul links may not be available in many deployments.
Another attempt to mitigate inter-cell co-channel interference is based on frequency-domain Inter-Cell Interference Coordination (ICIC). For example, the frequency-domain ICIC may be used to assign different Transmit (TX) power levels to different subcarriers, and to allocate the subcarriers to User Equipment (UE) based on UE locations with respect to a cell edge. In one example, non-overlapping subcarriers across neighboring cells may be allocated to the cell edge UEs, and overlapping subcarriers may be simultaneously allocated to UEs located at centers of the cells. In another example different power levels may be used to prevent cell edge UEs, which are served by neighboring cells, from being affected by inter-cell interference.
The frequency-domain ICIC may be implemented by exchanging a Relative Narrowband TX Power indication (RNTP) signaling messages to provide an indication on DL power restriction per Physical Resource Block (PRB) in a cell.
However, the current RNTP signaling is limited to specific deployments, and is not able to support other deployments.